<!DOCTYPE HTML>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>多条件三目运算</title>
    
    <style type="text/css">

    </style>
<script>

//	var a=12;
//	console.log(a>10?"111":"2222");
	//多个条件叠加，可以连续起来，中间用:隔开，顺序判断
    var score=prompt("输入分数：");
	
	console.log(
				score<0 || score>100 ? "无效分数":
				score>=90 ? "A":
				score>=80 ? "B":
				score>=60 ? "C":
							"D"
				);
</script>
</head>
<body>
	

</body>
</html>